Communication device, communication control method, and communication system

ABSTRACT

Provided is a communication device including a communication control unit that inserts, into a destination field of a data packet, intermediate node designation information designating an intermediate node different from a destination node of the data packet on a path to the destination node, and a transmission unit that transmits the data packet into which the intermediate node designation information is inserted.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 13/820,162, filed Mar. 1, 2013, which is a NationalStage of PCT/JP2011/068289, filed Aug. 10, 2011, and claims the benefitof priority from prior Japanese Patent Application JP 2010-225079, filedOct. 4, 2010, the entire content of which is hereby incorporated byreference.

TECHNICAL FIELD

The present disclosure relates to a communication device, acommunication control method, and a communication system.

BACKGROUND ART

Recently, a form of communication referred to as machine-typecommunication (MTC) communication or machine-to-machine (M2M)communication in which a terminal device connected to a communicationnetwork independently performs communication without involving humanintervention has been widely used. For example, a household gas meter isused as an MTC terminal and the remaining amount of gas is periodicallytransmitted from the meter to a server of a provider, so that theprovider can recognize an amount of gas used in each household withoutrequiring an inspector to perform a meter reading operation. Inaddition, the MTC communication, for example, can be used for variouspurposes such as transmission of an inventory quantity from a vendingmachine, transmission of the remaining amount of toner from a copier,transportation management in the transportation industry, and monitoringfor security. The use of the MTC communication is also expected toexpand in the future.

When the use of the MTC communication becomes widespread, the number ofterminals to be accommodated by a communication network significantlyincreases. As a result, congestion of traffic within the communicationnetwork occurs and a communication failure or deterioration of qualityof service (QoS) is likely to be problematic.

The following Patent Literature 1 proposes technology for monitoring astate of a communication node in a mobile communication network andchanging a forwarding path of a signal from a terminal when congestionor abnormality has been detected.

CITATION LIST Patent Literature

Patent Literature 1: JP 2009-130657A

SUMMARY OF INVENTION Technical Problem

However, the technology disclosed in the above-described PatentLiterature 1 is intended to reduce an influence of congestion when thecongestion is already occurring, and is not intended to avoid theoccurrence of congestion itself.

Here, considering the above-described purposes of the MTC communication,the MTC communication contains a risk of concentration of datatransmission in a specific time and a specific region. However, becausethe MTC communication is usually systematically performed, the MTCcommunication is different from communication from a terminal used by ahuman and it is sufficiently possible to predict a risk of concentrationof data transmission in the MTC communication. In addition, the case inwhich a low delay is strictly necessary as in voice communication,real-time streaming, and the like is comparatively less in the MTCcommunication. Accordingly, it is estimated that it is possible to avoidor mitigate the congestion of traffic in the MTC communication bysystematically and smoothly controlling a communication path of the MTCcommunication to a certain extent.

It is desirable to provide a novel and improved mechanism capable ofavoiding or mitigating congestion of traffic in MTC communication.

Solution to Problem

According to an embodiment of the present disclosure, there is provideda communication device including a communication control unit thatinserts, into a destination field of a data packet, intermediate nodedesignation information designating an intermediate node different froma destination node of the data packet on a path to the destination node,and a transmission unit that transmits the data packet into which theintermediate node designation information is inserted.

This communication device may be an MTC terminal, or a base station oranother communication node within a communication network that receivesa data packet transmitted from the MTC terminal. According to thisconfiguration, the data packet transmitted from the MTC terminal isrouted through the intermediate node without necessarily beingtransmitted along the shortest path to the destination node of the datapacket.

The communication device may further include a reception unit thatreceives the data packet transmitted from a terminal device ortransmitted to the terminal device. The communication control unit mayinsert the intermediate node designation information into thedestination field of the data packet when the terminal device is amachine-type communication (MTC) terminal.

The communication control unit may specify an intermediate node to bedesignated for the data packet from a plurality of intermediate nodecandidates using intermediate node data for specifying the intermediatenode to be designated. The communication control unit may transcribeinformation described in the destination field upon receipt of the datapacket to another field. The communication control unit may add a flagindicating that the destination field is changed to the data packet. Thecommunication control unit may insert control information used forenabling the intermediate node to identify the destination node of thedata packet into the data packet.

The communication device may be one of a plurality of intermediate nodecandidates. The communication device may be an MTC terminal thatgenerates the data packet.

According to another embodiment of the present disclosure, there isprovided a communication control method including inserting, into adestination field of a data packet, intermediate node designationinformation designating an intermediate node different from adestination node of the data packet on a path to the destination node,and transmitting the data packet into which the intermediate nodedesignation information is inserted.

According to another embodiment of the present disclosure, there isprovided a communication device including a reception unit that receivesa data packet transmitted from a terminal device or transmitted to theterminal device, wherein the communication device is designated in adestination field, a communication control unit that identifies adestination node of the data packet from information included in a fielddifferent from the destination field within the data packet, and insertsdestination node designation information designating the identifieddestination node into the destination field, and a transmission unitthat transmits the data packet into which the destination nodedesignation information is inserted.

The communication device may further include a storage unit that storesdestination node data in which control information within the datapacket is associated with the destination node of the data packet. Thecommunication control unit may identify the destination node of the datapacket using the destination node data.

The control information may include information specifying a terminalidentifier (ID), a class, or a group of the terminal device, anapplication (AP) ID or a class of an AP relating to the data packet, ora provider that provides the AP.

The communication device may further include an information managementunit that acquires update data for updating the destination node datafrom an information management server and updates the destination nodedata using the acquired update data.

The communication control unit may identify the destination node of thedata packet from information transcribed from the destination field to afield different from the destination field.

According to another embodiment of the present disclosure, there isprovided a communication control method for use in a communicationdevice within a communication network including a plurality ofcommunication nodes, including receiving a data packet transmitted froma terminal device or transmitted to the terminal device, wherein thecommunication device is designated in a destination field, identifying adestination node of the data packet from information included in a fielddifferent from the destination field within the data packet, insertingdestination node designation information designating the identifieddestination node into the destination field, and transmitting the datapacket into which the destination node designation information isinserted.

According to another embodiment of the present disclosure, there isprovided a communication system including a first communication deviceincluding a communication control unit that inserts, into a destinationfield of a data packet, intermediate node designation informationdesignating an intermediate node different from a destination node ofthe data packet on a path to the destination node, and a transmissionunit that transmits the data packet into which the intermediate nodedesignation information is inserted, and a second communication deviceincluding a reception unit that receives a data packet transmitted froma terminal device or transmitted to the terminal device, wherein an owndevice is designated in a destination field, a communication controlunit that identifies a destination node of the data packet frominformation included in a field different from the destination fieldwithin the data packet, and inserts destination node designationinformation designating the identified destination node into thedestination field, and a transmission unit that transmits the datapacket into which the destination node designation information isinserted. The second communication device may be a candidate for theintermediate node.

According to another embodiment of the present disclosure, there isprovided a communication device including a storage unit that storesdestination node data in which control information within a data packettransmitted from an MTC terminal or transmitted to the MTC terminal isassociated with a destination node of the data packet, a management unitthat manages an update of the destination node data stored by thestorage unit, and a transmission unit that transmits update datarelating to the destination node data to an intermediate node differentfrom the destination node on a path to the destination node of the datapacket.

The control information may include information specifying a terminalID, a class, or a group of an MTC terminal, an AP ID or a class of an APrelating to the data packet, or a provider that provides the AP.

Advantageous Effects of Invention

As described above, in accordance with the technology of the presentdisclosure, congestion of traffic can be avoided or mitigated in MTCcommunication.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating an outline of a communicationsystem in accordance with a first embodiment.

FIG. 2 is a block diagram illustrating an example of a configuration ofa terminal device in accordance with the first embodiment.

FIG. 3 is an explanatory diagram illustrating an example of a packetformat.

FIG. 4 is a flowchart illustrating an example of a flow of a datatransmission process in accordance with the first embodiment.

FIG. 5 is a block diagram illustrating an example of a configuration ofa base station in accordance with the first embodiment.

FIG. 6 is a flowchart illustrating an example of a flow of a controlinformation insertion process in accordance with the first embodiment.

FIG. 7 is a block diagram illustrating an example of a configuration ofa forwarding node in accordance with the first embodiment.

FIG. 8A is an explanatory diagram illustrating a first example offorwarding destination data.

FIG. 8B is an explanatory diagram illustrating a second example offorwarding destination data.

FIG. 9 is a flowchart illustrating an example of a data forwardingprocess in accordance with the first embodiment.

FIG. 10 is a schematic diagram illustrating an outline of acommunication system in accordance with a second embodiment.

FIG. 11 is a block diagram illustrating an example of a configuration ofa terminal device in accordance with the second embodiment.

FIG. 12 is a flowchart illustrating an example of a flow of a datatransmission process in accordance with the second embodiment.

FIG. 13 is a block diagram illustrating an example of a configuration ofa base station in accordance with the second embodiment.

FIG. 14A is an explanatory diagram illustrating a first example ofintermediate node data.

FIG. 14B is an explanatory diagram illustrating a second example ofintermediate node data.

FIG. 15A is an explanatory diagram illustrating a first example of adestination field update process in accordance with the secondembodiment.

FIG. 15B is an explanatory diagram illustrating a second example of adestination field update process in accordance with the secondembodiment.

FIG. 15C is an explanatory diagram illustrating a third example of adestination field update process in accordance with the secondembodiment.

FIG. 15D is an explanatory diagram illustrating a fourth example of adestination field update process in accordance with the secondembodiment.

FIG. 15E is an explanatory diagram illustrating a fifth example of adestination field update process in accordance with the secondembodiment.

FIG. 16A is a flowchart illustrating an example of a flow of a dataforwarding process by the base station in accordance with the secondembodiment.

FIG. 16B is a flowchart illustrating another example of a flow of a dataforwarding process by the base station in accordance with the secondembodiment.

FIG. 17 is a block diagram illustrating an example of a configuration ofan intermediate node in accordance with the second embodiment.

FIG. 18 is an explanatory diagram illustrating an example of destinationnode data.

FIG. 19A is a flowchart illustrating an example of a flow of a dataforwarding process by the intermediate node in accordance with thesecond embodiment.

FIG. 19B is a flowchart illustrating another example of a flow of a dataforwarding process by the intermediate node in accordance with thesecond embodiment.

FIG. 20 is an explanatory diagram illustrating an example of acommunication path capable of being implemented in accordance with thesecond embodiment.

FIG. 21 is a block diagram illustrating an example of a configuration ofan information management server in accordance with the secondembodiment.

FIG. 22 is an explanatory diagram illustrating an example of updatedata.

FIG. 23A is a flowchart illustrating a first example of a flow of anupdate data distribution process in accordance with the secondembodiment.

FIG. 23B is a flowchart illustrating a second example of a flow of anupdate data distribution process in accordance with the secondembodiment.

FIG. 24 is a flowchart illustrating an example of a flow of adestination node data update process in accordance with the secondembodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the drawings, elements that have substantiallythe same function and structure are denoted with the same referencesigns, and repeated explanation is omitted.

Hereinafter, “modes for carrying out the present invention” will bedescribed in the following order.

1. Description of First Embodiment

-   -   1-1. Outline of System    -   1-2. Terminal Device    -   1-3. Base Station    -   1.4. Forwarding Node    -   1.5. Summary of First Embodiment    -   1-6. Application Example

2. Description of Second Embodiment

-   -   2-1. Outline of System    -   2-2. Terminal Device    -   2-3. Base Station    -   2-4. Intermediate Node    -   2-5. Example of Communication Path    -   2-6. Information Management Server    -   2-7. Management of Discontinuous Reception (DRX)    -   2-8. Summary of Second Embodiment    -   2-9. Application Example

1. Description of First Embodiment 1-1. Outline of System

First, the first embodiment will be described using FIGS. 1 to 9. FIG. 1is a schematic diagram illustrating an outline of a communication system1 in accordance with the first embodiment. Referring to FIG. 1, thecommunication system 1 includes a plurality of terminal devices 100 a to100 e, a plurality of base stations 120 a to 120 d, a plurality ofcommunication devices 140 a to 140 d, and a plurality of application(AP) servers 190 a to 190 c. The plurality of communication devices 140a to 140 d form a core network 110 in the communication system 1. Thebase station 120 d and the AP servers 190 a and 190 b are connected to anetwork 20.

In this specification, when it is not necessary to distinguish theterminal devices 100 a to 100 e from one another, they are collectivelyreferred to as a terminal device 100. The same is also true for a basestation 120 (120 a to 120 d), a communication device 140 (140 a to 140d), and an AP server 190 (190 a to 190 c).

The terminal device 100 is a wireless communication device that operatesas an MTC terminal. Each terminal device 100 transmits and receives aradio signal to and from the base station 120 that provides a wirelesscommunication service to a cell to which the terminal device 100belongs. For example, the terminal device 100 generates AP data such asan amount of used gas or an inventory quantity of a vending machine, andtransmits a data packet including the generated AP data to the basestation 120. The data packet transmitted from the terminal device 100 tothe base station 120 is ultimately delivered to a desired AP server 190via several communication nodes.

The base station 120, for example, is a communication node that providesthe wireless communication service within a cell extending around itsown device according to a cellular communication scheme represented bylong term evolution (LTE), LTE-Advanced, or the like. The base station120, for example, receives a data packet including the AP data generatedby the terminal device 100, and forwards the received data packet to thecommunication device 140 of the core network 10. In addition, the basestation 120 receives a data packet addressed to the terminal device 100forwarded via the core network 10, and forwards the received data packetto the destination terminal device 100.

In the example of FIG. 1, the base stations 120 a to 120 c are so-calledmacrocell base stations directly connected to the core network 10. Onthe other hand, the base station 120 d is a femtocell base station (alsoreferred to as home eNB (HeNB) in LTE) connected to the core network 10via the network 20. These base stations 120 may also provide thewireless communication service to a general user terminal as well as anMTC terminal like the terminal device 100.

The communication device 140 is a communication node that forms the corenetwork 10. Each communication device 140, for example, may be a radionetwork controller (RNC), a mobility management entity (MME), a homesubscriber server (HSS), a serving GPRS support node (SGSN), a gatewayGPRS support node (GGSN), or the like. In addition, each communicationdevice 140, for example, may be a network device such as a switch orrouter connected between the communication nodes. The communicationdevice 140, for example, receives a data packet transmitted from theterminal device 100 or transmitted to the terminal device 100, andsequentially forwards the received data packet so that the received datapacket is delivered to a destination AP server 190.

Among the communication devices 140 illustrated in FIG. 1, for example,the communication device 140 d is the GGSN having a function of aso-called gateway, and is located in a boundary between the core network10 and the network 20. The network 20, for example, may be an Internetprotocol (IP) network such as the Internet, or may be a non-IP networksuch as an asynchronous transfer mode (ATM) network.

The AP server 190, for example, is a server device having an AP functionsuch as planning for charging of a gas fee or delivery of products for avending machine. A server device using AP data transmitted from the MTCterminal is also referred to as an MTC server. The AP server 190 may beconnected to the network 20 or may be located within the core network10. In the example of FIG. 1, the AP servers 190 a and 190 b areconnected to the network 20, and the AP server 190 c is located withinthe core network 10. The AP server 190 c may be implemented onphysically the same device as a communication node that forms the corenetwork 10.

The AP server 190, for example, ultimately receives a data packettransmitted from the terminal device 100. The AP server 190 executes theAP function as described in the above example by acquiring the AP dataincluded in the received data packet. In addition, the AP server 190 mayprovide a user with a user interface for accepting an input of a settingrelating to the MTC terminal. The setting relating to the MTC terminal,for example, can include a setting relating to a schedule of MTCcommunication between the AP server 190 and the terminal device 100.

When there are a large number of MTC terminals in the communicationsystem 1 illustrated in FIG. 1, data packets transmitted from the MTCterminals are likely to cause congestion on a communication path to thedestination AP server 190.

In particular, when an AP necessary to collect periodic data isintroduced, data packets can be simultaneously transmitted from theterminal devices 100 in a specific time or a specific region. However,because MTC communication is systematically performed, congestion by theMTC communication can be avoided before the congestion occurs. Inaddition, when the purpose of the MTC communication is data collection,the data packet may not necessarily be delivered to the AP server 190 ata maximum rate. In this embodiment, the occurrence of congestion oftraffic in the MTC communication is avoided or mitigated by adopting aconfiguration of each device described from the next section.

In this specification, it should be noted that the term “communicationnode” or “communication device” can be any of the terminal device 100,the base station 120, the communication device 140, and the AP server190 illustrated in FIG. 1 when no particular reference sign is attached.

1-2. Terminal Device

(1) Configuration Example of Device

FIG. 2 is a block diagram illustrating an example of a configuration ofthe terminal device 100 in accordance with this embodiment. Referring toFIG. 2, the terminal device 100 includes an AP unit 102, a storage unit104, a communication control unit 110, a wireless transmission unit 112,and a wireless reception unit 114.

The AP unit 102 generates AP data to be transmitted to the AP server190, and outputs the generated AP data to the communication control unit110. The AP data generated by the AP unit 102, for example, can includean arbitrary type of data such as an amount of used gas, an inventoryquantity of a vending machine, the remaining amount of toner of acopier, or position data for transport management according to a purposeof an AP. The generation of AP data, for example, may be periodicallyperformed at a preset time or frequency. Alternatively, the generationof the AP data may be performed using a predetermined event (forexample, a decrease of more than a given quantity in an inventoryquantity) as a trigger.

The storage unit 104 stores programs and data for processing by the APunit 102 and the communication control unit 110 using a storage mediumsuch as a hard disk or a semiconductor memory. In addition, the storageunit 104 stores data serving as a base for the generation of the AP databy the AP unit 102. In addition, the storage unit 104 pre-stores atleast part of control information inserted into a data packet as will bedescribed later.

When the AP data to be transmitted to the AP server 190 is input fromthe AP unit 102, the communication control unit 110 generates a datapacket including the AP data. The communication control unit 110 causesthe generated data packet to be transmitted from the wirelesstransmission unit 112. In addition, when a data packet is received bythe wireless reception unit 114, the communication control unit 110acquires AP data included in the data packet and outputs the acquired APdata to the AP unit 102.

The wireless transmission unit 112 and the wireless reception unit 114have an antenna and a radio frequency (RF) circuit. The wirelesstransmission unit 112 transmits a data packet generated by thecommunication control unit 110 as a radio signal on an air interface tothe base station 120. In addition, the wireless reception unit 114receives a data packet transmitted from the base station 120 as a radiosignal on the air interface, and outputs the received data packet to thecommunication control unit 110.

(2) Example of Packet Format

FIG. 3 is an explanatory diagram illustrating an example of a packetformat of a data packet transmitted by the terminal device 100 in thisembodiment. Referring to FIG. 3, the data packet in accordance with thisembodiment includes a header area HS and a data area DS. As illustratedin FIG. 3, the header area HS has eight fields F1 to F8 in which controlinformation is stored. The data area DS is an area for storing theabove-described AP data.

In the destination field F1 of the header area HS, informationdesignating a destination node of the data packet is stored. Theinformation stored in the destination field F1, for example, may be anInternet protocol (IP) address of the destination node, a media accesscontrol (MAC) address, a host name, or another unique identifier. Whenthe terminal device 100 transmits AP data, the AP server 190 thatprovides a corresponding AP function becomes the destination node. Inaddition, when the terminal device 100 receives a data packet, theterminal device 100 becomes the destination node.

In the transmission source field F2, transmission source nodeinformation designating a transmission source node of the data packet isstored. When the terminal device 100 transmits AP data to the AP server190, the terminal device 100 generating the AP data becomes thetransmission source node.

The application (AP) class field F3 and the AP identifier (ID) field F4are fields for storing an AP class and an AP ID, respectively. The APclass and the AP ID are control information regarding an AP relating toa data packet. The AP class is a class to which an individual AP belongswhen APs have been classified into several classes. For example, a QoSclass classified according to QoS requirements may be used as the APclass. The AP ID is an ID for uniquely identifying an individual AP.Values of the AP class and the AP ID supported by each terminal device100 can be pre-stored by the storage unit 104.

The terminal class field F5, the terminal group (Grp) field F6, and theterminal ID field F7 are fields for storing a terminal class, a terminalgroup, and a terminal ID. The terminal class, the terminal group, andthe terminal ID are control information regarding an MTC terminal. WhenMTC terminals have been classified into several classes and groups, theterminal class and the terminal group are a class and a group to whichan individual terminal device belongs, respectively. For example,according to 3^(rd) Generation Partnership Project (3GPP) TechnicalSpecification (TS) 22.368, the MTC terminal can be classified assecurity equipment, transportation-related equipment, payment equipment,health care equipment, remote control equipment, measurement equipment,consumer equipment, and the like according to its service field. Inaddition, for example, as in a vending machine or point of sales (POS)equipment for the payment equipment, a power meter or a gas meter forthe measurement equipment, the MTC terminal can be classified in furtherdetail according to its purpose. The terminal class, for example, may bea class of the MTC terminal corresponding to the service field orpurpose. In addition, 3GPP TS 22.368, for example, proposes allocationof MTC terminals to one or more groups defined in terms of a QoS policy,a maximum bit rate, and the like. The terminal group, for example, maybe a group defined to manage the MTC terminals based on theabove-described group. Of course, the classification of the MTC terminalaccording to another concept may be used. The terminal ID is an ID foruniquely identifying an individual terminal device. Values of theterminal class, the terminal group, and the terminal ID of each terminaldevice 100 can be pre-stored by the storage unit 104.

The provider ID field F8 is a field for storing a provider ID thatuniquely specifies a provider that provides an AP relating to a datapacket transmitted by each terminal device 100. In addition, theprovider ID can also be pre-stored by the storage unit 104.

(3) Flow of Data Transmission Process

FIG. 4 is a flowchart illustrating an example of the flow of the datatransmission process by the terminal device 100 in accordance with thisembodiment.

Referring to FIG. 4, first, the AP unit 102 of the terminal device 100generates AP data periodically or according to occurrence of apredetermined event (step S102). Next, the communication control unit110 acquires control information regarding an AP such as an AP class, anAP ID, or the like for the generated AP data from the storage unit 104(step S104). In addition, the communication control unit 110 acquirescontrol information such as a terminal class, a terminal group, aterminal ID, and the like regarding an MTC terminal of the terminaldevice 100 from the storage unit 104 (step S106). Next, thecommunication control unit 110 generates a data packet having a packetformat illustrated in FIG. 3 using the acquired control information andthe AP data (step S108). Here, a destination of the generated datapacket, for example, can be designated by the AP unit 102 in associationwith the AP data. The wireless transmission unit 112 transmits the datapacket generated by the communication control unit 110 to the basestation 120 (step S110).

Although an example in which the terminal device 100 inserts the controlinformation into the data packet has been described, anothercommunication node (for example, the base station 120, the communicationdevice 140, or the like) may insert the control information into thedata packet instead of the terminal device 100. A device that insertsthe control information into the data packet may be a device (forexample, a relay station or the like capable of intervention between theterminal device 100 and the base station 120) not illustrated in FIG. 1.In the next section, an example in which the base station 120 insertspart of the control information into the data packet will be described.

1-3. Base Station

(1) Configuration Example of Device

FIG. 5 is a block diagram illustrating an example of a configuration ofthe base station 120 in accordance with this embodiment. Referring toFIG. 5, the base station 120 includes a wireless reception unit 122, awireless transmission unit 124, a transmission unit 126, a receptionunit 128, a storage unit 130, and a communication control unit 132.

The wireless reception unit 122 and the wireless transmission unit 124have an antenna and an RE circuit for performing wireless communicationamong a plurality of terminal devices 100. The wireless reception unit122 receives a data packet transmitted from the terminal device 100, andoutputs the received data packet to the communication control unit 132.In addition, when a data packet addressed to the terminal device 100 isinput from the communication control unit 132, the wireless transmissionunit 124 transmits the data packet to the terminal device 100.

The transmission unit 126 and the reception unit 128 are communicationinterfaces for enabling the base station 120 to perform communicationwith the communication device 140 of the core network 10. When the datapacket is input from the communication control unit 132, thetransmission unit 126 transmits the data packet to the core network 10.When the data packet is received from the core network 10, the receptionunit 128 outputs the data packet to the communication control unit 132.

The storage unit 130 stores a program and data for processing by thecommunication control unit 132 using a storage medium. In addition, thestorage unit 130 may pre-store part of the control informationillustrated in FIG. 3 in association with a terminal ID or addressinformation of each terminal device 100.

The communication control unit 132, for example, causes the base station120 to operate as a base station for cellular communication according tostandard specs of LTE, or the like. In addition, in this embodiment, thecommunication control unit 132 can insert the above-described controlinformation into the data packet transmitted from the terminal device100 instead of the terminal device 100. For example, when the datapacket from the terminal device 100 is input from the wireless receptionunit 122, the communication control unit 132 acquires controlinformation associated with a terminal ID or a transmission sourceaddress described within the data packet from the storage unit 130. Thecommunication control unit 132 inserts the acquired control informationinto the data packet.

(2) Flow of Control Information Insertion Process

FIG. 6 is a flowchart illustrating an example of the flow of the controlinformation insertion process by the base station 120 in accordance withthis embodiment.

Referring to FIG. 6, first, the wireless reception unit 122 of the basestation 120 receives a data packet transmitted from the terminal device100 (step S122). The wireless reception unit 122 outputs the receiveddata packet to the communication control unit 132. Next, thecommunication control unit 132 determines whether the received datapacket is a packet for MTC communication (step S124). The packet for theMTC communication includes both a packet for which a transmission sourceis an MTC terminal and a packet for which an ultimate destination is anMTC terminal. The communication control unit 132, for example, candetermine whether the data packet is a packet for MTC communication byreferring to a terminal group or a terminal class included in the datapacket or comparing a terminal ID included in the data packet with apre-registered ID list. Alternatively, the communication control unit132, for example, may determine whether the data packet is a packet forMTC communication by referring to an AP class included in the datapacket or comparing an AP ID included in the data packet with apre-registered ID list. Here, if the data packet is the packet for theMTC communication, then the process of steps S126 and S128 is performed.

When a device of the transmission source is the MTC terminal, thecommunication control unit 132 inserts control information (the APclass, the AP ID, and the like) regarding an AP into the data packet(step S126). In addition, the communication control unit 132 insertscontrol information (the terminal class, the terminal group, or thelike) regarding the MTC terminal into the data packet (step S128).

Next, the communication control unit 132 regenerates the data packet(step S130). The regenerated data packet is forwarded from thetransmission unit 126 to the core network 10 (step S132).

When the terminal device 100 inserts all control information to be usedfor a data forwarding process by the communication device 140 (theforwarding node) into the data packet as will be described next, thecontrol information insertion process by the base station 120illustrated in FIG. 6 is omitted. In this case, like the data packettransmitted from a normal user terminal, the data packet transmittedfrom the terminal device 100 is forwarded by the base station 120 to thecore network 10.

1-4. Forwarding Node

(1) Configuration Example of Device

FIG. 7 is a block diagram illustrating an example of a configuration ofthe communication device 140 in accordance with this embodiment.Referring to FIG. 7, the communication device 140 includes a receptionunit 142, a transmission unit 144, a storage unit 150, and acommunication control unit 152.

The reception unit 142 and the transmission unit 144 are communicationinterfaces for enabling the communication device 140 to performcommunication with other communication devices. When a data packet isreceived from another communication device, the reception unit 142outputs the data packet to the communication control unit 152. When adata packet is input from the communication control unit 152, thetransmission unit 144 transmits the data packet to another communicationdevice.

The storage unit 150 stores a program and data for processing by thecommunication control unit 152 using a storage medium. In addition, thestorage unit 150 stores forwarding destination data associated withclassification based on control information within a data packet and aforwarding destination node of the data packet. An example of theforwarding destination data stored by the storage unit 150 will bedescribed later.

When a device of a transmission source of the data packet received bythe reception unit 142 is an MTC terminal, the communication controlunit 152 selects a forwarding destination node of a data packet from aplurality of forwarding destination node candidates so that traffic isdistributed. More specifically, in this embodiment, the communicationcontrol unit 152 selects the forwarding destination node of the datapacket based on control information within the data packet. For example,the communication control unit 152 may classify the data packetaccording to the control information within the data packet, and selectthe forwarding destination node associated with the classification ofthe data packet in the forwarding destination data stored by the storageunit 150 as the forwarding destination node of the data packet.Alternatively, the communication control unit 152 may select theforwarding destination node of each data packet, for example, so thatforwarding destinations of data packets belonging to the sameclassification may be distributed to a plurality of forwardingdestination nodes. The selection of the forwarding destination node bythe communication control unit 152 is typically performed regardless ofa routing metric relating to a path to a destination node of the datapacket. That is, the communication device 140 in accordance with thisembodiment does not necessarily select a forwarding destination node inwhich a metric such as the number of hops to the destination node orcosts of a communication path is minimized.

FIGS. 8A and 8B are explanatory diagrams each illustrating an example offorwarding destination data available for selection of a forwardingdestination node by the communication device 140.

Referring to FIG. 8A, forwarding destination data 151 a is shown as afirst example. The forwarding destination data 151 a has three dataitems of an “AP class,” a “terminal ID,” and a “forwarding destinationnode.” In the first example, the communication control unit 152classifies data packets into six categories according to AP classes andterminal IDs included in control information within the data packets.For example, when the AP class is “C1,” the data packet is classifiedinto one of first to fourth categories according to two lower-order bitsof the terminal ID. The forwarding destination node of the data packetclassified into the first category (the two lower-order bits of theterminal ID=[00]) is a node N1. The forwarding destination node of thedata packet classified into the second category (the two lower-orderbits of the terminal ID=[01]) is a node N2. The forwarding destinationnode of the data packet classified into the third category (the twolower-order bits of the terminal ID=[10]) is a node N1. The forwardingdestination node of the data packet classified into the fourth category(the two lower-order bits of the terminal ID=[11]) is a node N4. Inaddition, when the AP class is “C2,” the data packet is classified intoa fifth category regardless of the terminal ID. The forwardingdestination node of the data packet classified into the fifth categoryis a node N5. When the AP class is “C3,” the data packet is classifiedinto a sixth category regardless of the terminal ID. The forwardingdestination node of the data packet classified into the sixth categoryis a node N6.

The AP class “C1,” for example, is a class in which a low delay isrecommended in relation to QoS (for example, an upper limit of anallowed delay is designated). In this case, it is possible to avoid theoccurrence of congestion and reduce a risk of QoS violation bydistributing the forwarding destination of the data packet to aplurality of forwarding destination nodes according to a terminal ID asin the first example. The communication control unit 152, for example,may distribute the forwarding destination of the data packet of the APclass “C1” among the four forwarding destination nodes N1 to N4 in around-robin scheme or a random scheme without using the terminal ID.

In addition, in the first example, data packets of different AP classesare forwarded to different forwarding destination nodes. For example,the nodes N5 and N6 may be nodes having throughput not higher than thatof the nodes N1 to N4 or nodes having low-speed links. The congestion oftraffic is less likely be caused by selecting a different forwardingdestination node for every AP.

Referring to FIG. 8B, forwarding destination data 151 b is illustratedas the second example. The forwarding destination data 151 b has twodata items such as a “terminal class” and a “forwarding destinationnode”. In the second example, the communication control unit 152classifies data packets into four categories according to terminalclasses included in control information of the data packets. Forexample, when the terminal class is “T1”, the data packet is classifiedinto a first category, and the node N1 serving as the forwardingdestination node is selected. When the terminal class is “T2”, the datapacket is classified into a second category, and the node N2 serving asthe forwarding destination node is selected. When the terminal class is“T3”, the data packet is classified into a third category, and the nodeN3 serving as the forwarding destination node is selected. When theterminal class is “T4”, the data packet is classified into a fourthcategory, and the node N4 serving as the forwarding destination node isselected.

In the second example, because data packets of different terminalclasses are forwarded to different forwarding destination nodes,forwarding destinations of data packets are distributed between terminalclasses. Thus, the possibility of congestion of data packets is reduced.The communication control unit 152, for example, may distributeforwarding destinations of data packets from the terminal devices 100 ofthe same terminal class in the round-robin scheme or the random schemeamong the four forwarding destination nodes N1 to N4. In addition, aterminal group may be used instead of the terminal class.

All the communication devices 140 within the core network 10 may nothave a function serving as a forwarding destination node described here.In addition, content of forwarding destination node data may differ forevery communication device 140 that functions as the forwardingdestination node. That is, a first forwarding destination node may haveforwarding destination data illustrated in FIG. 8A, while a secondforwarding destination node may have forwarding destination dataillustrated in FIG. 8B. The forwarding destination node data may beseparately registered and updated in each forwarding destination node ormay be collectively managed and dynamically updated in an informationmanagement server as described in the second embodiment.

(2) Flow of Data Forwarding Process

FIG. 9 is a flowchart illustrating an example of the data forwardingprocess by the communication device 140 in accordance with thisembodiment.

Referring to FIG. 9, first, the reception unit 142 of the communicationdevice 140 receives a data packet transmitted from the terminal device100 (step S142). The reception unit 142 outputs the received data packetto the communication control unit 152. Next, the communication controlunit 152 determines whether the received data packet is a packet for MTCcommunication (step S144). Here, if the data packet is the packet forthe MTC communication, the process proceeds to step S146. On the otherhand, if the data packet is not the packet for the MTC communication,the process proceeds to step S154.

In step S146, the communication control unit 152 acquires controlinformation included in a header area of the data packet (step S146).Next, the communication control unit 152 classifies the data packet intoone of a plurality of categories according to the acquired controlinformation (step S148). Next, the communication control unit 152determines whether there is a forwarding destination node correspondingto a category to which the data packet belongs in forwarding destinationnode data stored in the storage unit 150 (step S150). Here, when thereis a corresponding forwarding destination node in the forwardingdestination node data, the process proceeds to step S152. On the otherhand, when there is no corresponding forwarding destination node in theforwarding destination node data, the process proceeds to step S154.

In step S152, the communication control unit 152 selects the forwardingdestination node associated with the category to which the data packetbelongs in the forwarding destination node data as the forwardingdestination node of the data packet (step S152). On the other hand, instep S154, the communication control unit 152 selects a predeterminedforwarding destination node as the forwarding destination node of thedata packet (step S154). Here, the predetermined forwarding destinationnode, for example, may be a forwarding destination node fixedly definedin advance or may be a forwarding destination node dynamically selectedaccording to a routing metric.

The transmission unit 144 forwards the data packet to the forwardingdestination node selected by the communication control unit 152 (stepS156).

1-5. Summary of First Embodiment

The first embodiment has been described above using FIGS. 1 to 9. Inaccordance with this embodiment, when a data packet has been transmittedfrom an MTC terminal, a forwarding destination node is selected from aplurality of forwarding destination node candidates according to aforwarding node within a communication network, and the data packet isforwarded to the selected forwarding destination node. Thereby, it ispossible to route traffic of MTC communication to a plurality of routesand avoid or mitigate congestion. In addition, as a result, it ispossible to increase the number of MTC terminals capable of beingaccommodated in a communication system.

In addition, in accordance with this embodiment, a forwarding nodeselects a forwarding destination node based on control informationwithin a data packet. This control information can be used to classifythe data packet in terms of an AP relating to MTC communication or atype of MTC terminal. According to this configuration, it is possible tosystematically distribute the data packet according to a type of AP or atype of terminal. For example, it is also possible to distributeforwarding destinations of data packets from the same type of APs or thesame type of terminals, which are likely to simultaneously transmitdata, among a plurality of forwarding destination nodes. Accordingly, itis possible to avoid the occurrence of congestion by MTC communicationin advance or effectively mitigate the congestion.

In addition, it is possible to introduce a mechanism for theabove-described congestion avoidance without giving impact such asmodification of a processing logic to an existing device such as an MTCterminal or a base station normally using information included in a datapacket as control information.

In addition, in accordance with this embodiment, the selection of theforwarding destination node in the forwarding node can be performedregardless of a routing metric relating to a path to a destination node.This is a concept focusing on characteristics of MTC communication inwhich data may not necessarily be delivered to a destination at amaximum rate in many cases as compared with communication by a normal(human-used) user terminal. Accordingly, data packets of MTCcommunication are not concentrated on a so-called “optimum”communication path in terms of a routing metric. As a result, forexample, a risk of MTC communication interfering with non-MTCcommunication such as voice communication or real-time streaming havinghigh priority is reduced.

1-6. Application Example

In the first embodiment, an example in which a forwarding destination ofa data packet transmitted from an MTC terminal is mainly distributedamong a plurality of forwarding destination node candidates has beendescribed. However, a mechanism of selection of the above-describedforwarding destination node is also applicable to a data packettransmitted to the MTC terminal. For example, the communication device140 illustrated in FIG. 1 has additional forwarding destination datadescribing a plurality of forwarding destination node candidates for adata packet transmitted to the terminal device 100, and traffic isdistributed based on control information within the data packet and theadditional forwarding destination data, so that the forwardingdestination node of the data packet transmitted to the terminal device100 may be selected from the plurality of forwarding destination nodecandidates.

2. Description of Second Embodiment

Next, the second embodiment will be described using FIGS. 10 to 24. Inthe first embodiment, a forwarding node distributes traffic of MTCcommunication and hence concentration of traffic on a specificcommunication path is prevented in advance. In the second embodiment tobe described in this section, the traffic of MTC communication is guidedto a path via an intermediate node to be described later, and hence theconcentration of traffic on a specific communication path is ultimatelyprevented.

2-1. Outline of System

FIG. 10 is a schematic diagram illustrating an outline of acommunication system 2 in accordance with the second embodiment.Referring to FIG. 10, the communication system 2 includes a plurality ofterminal devices 200 a to 200 d, a plurality of base stations 220 a to220 c, communication devices 140, 240 a, and 240 b within the corenetwork 10, an information management server 270, and a plurality of APservers 190 a to 190 c.

Like the terminal device 100 of the first embodiment, the terminaldevice 200 is a wireless communication device that operates as an MTCterminal. Each terminal device 200 transmits and receives a radio signalto and from the base station 220 that provides a wireless communicationservice to a cell to which the terminal device 200 belongs. The terminaldevice 200, for example, generates AP data, and transmits a data packetincluding the generated AP data to the base station 220. The data packettransmitted from the terminal device 200 to the base station 220 isultimately delivered to a desired AP server 190 via severalcommunication nodes. However, in this embodiment, the terminal device200 can designate information designating a communication node differentfrom a destination node, which is an ultimate destination, in adestination field of the data packet. In this specification, asdescribed above, a communication node designated as a temporarydestination (not the ultimate destination) of the data packettransmitted from the MTC terminal is referred to as an intermediatenode.

Like the base station 220 in accordance with the first embodiment, thebase station 220 is a communication node that provides a wirelesscommunication service within a cell extending around its own device, forexample, according to a cellular communication scheme represented byLTE, LTE-Advanced, or the like. The base station 220, for example,receives a data packet including AP data generated by the terminaldevice 200, and forwards the received data packet to a communicationnode of the core network 10. However, in this embodiment, the basestation 220 can insert information designating an intermediate node intothe destination field of the forwarded data packet, in addition, thebase station 220 receives the data packet addressed to the terminaldevice 200 forwarded via the core network 10, and forwards the receiveddata packet to a destination terminal device 200.

The communication device 240 is a communication node that is likely tobe designated as the intermediate node. Each communication device 240,for example, may be an RNC, an MME, an HSS, an SGSN, a GGSN, or thelike, or may be a switch or a router that establishes a connectionbetween communication nodes. The communication device 240, for example,receives a data packet designated by its own device in the destinationfield, identifies an appropriate destination node using controlinformation within the data packet, and forwards the data packet towardthe identified destination node.

The information management server 270 is a communication device thatmanages a master of the destination node data to be used when theintermediate node identifies the destination node. In the example ofFIG. 10, the information management server 270 is connected to thenetwork 20. However, the present disclosure is not limited to thisexample, and the information management server 270, for example, may belocated in the core network 10. In addition, the information managementserver 270 may be implemented on physically the same device as acommunication node that forms the core network 10. The informationmanagement server 270 may manage a master of the forwarding destinationdata described in the first embodiment in addition to the master of thedestination node data.

2-2. Terminal Device

(1) Configuration Example of Device

FIG. 11 is a block diagram illustrating an example of a configuration ofthe terminal device 200 in accordance with this embodiment. Referring toFIG. 11, the terminal device 200 includes an AP unit 102, a storage unit204, a communication control unit 210, a wireless transmission unit 112,and a wireless reception unit 114.

The storage unit 204 stores programs and data for processing by the APunit 102 and the communication control unit 210 using a storage medium.In addition, like the storage unit 104 of the terminal device 100 inaccordance with the first embodiment, the storage unit 204 stores dataserving as a base for generation of AP data by the AP unit 102. Inaddition, the storage unit 204 pre-stores control information insertedinto a data packet. Further, in this embodiment, the storage unit 204,for example, pre-stores intermediate node designation informationdesignating an intermediate node different from a destination node on apath to an ultimate destination node of the data packet in associationwith an AP. The intermediate node designation information, for example,may be an IP address, a MAC address, a host name, or another unique IDof the intermediate node.

When the AP data to be transmitted to the AP server 190 is input fromthe AP unit 102, the communication control unit 210 generates a datapacket including the AP data. At this time, the communication controlunit 210 can insert the intermediate node designation information storedin association with an AP in the storage unit 204 into the destinationfield of the data packet. The communication control unit 210 causes thegenerated data packet to be transmitted from the wireless transmissionunit 112. In addition, when the data packet is received by the wirelessreception unit 114, the communication control unit 210 acquires the APdata included in the data packet and outputs the acquired AP data to theAP unit 102.

(2) Flow of Data Transmission Process

FIG. 12 is a flowchart illustrating an example of the flow of the datatransmission process by the terminal device 200 in accordance with thisembodiment.

Referring to FIG. 12, first, the AP unit 102 of the terminal device 200generates AP data periodically or according to a predetermined event(step S202). Next, the communication control unit 210 acquires controlinformation regarding an AP such as an AP class, an AP ID, or the likefor the generated AP data from the storage unit 204 (step S204). Inaddition, the communication control unit 210 acquires controlinformation such as a terminal class, a terminal group, a terminal ID,and the like regarding an MTC terminal of the terminal device 200 fromthe storage unit 204 (step S206). Next, the communication control unit210 acquires the intermediate node designation information to beinserted into the destination field of the data packet from the storageunit 204 (step S208). Next, the communication control unit 210 generatesa data packet including the acquired intermediate node designationinformation and the control information in the header area and the dataarea (step S210). The wireless transmission unit 112 transmits the datapacket generated by the communication control unit 210 to the basestation 220 (step S212).

Although an example in which the terminal device 200 inserts the controlinformation into the data packet has been described here, anothercommunication node (for example, the base station 220, the communicationdevice 240, or the like) may insert the control information into thedata packet instead of the terminal device 200. In addition, as will bedescribed next, instead of the terminal device 200, the othercommunication node may insert the intermediate node designationinformation into the destination field. A device that inserts theintermediate node designation information into the destination field maybe a device (for example, a relay station capable of interventionbetween the terminal device 200 and the base station 220) notillustrated in FIG. 10. In the next section, an example in which thebase station 220 inserts part of the control information into the datapacket will be described. In the example of the next section, theterminal device 200 can insert the destination node designationinformation designating the ultimate destination node into thedestination field as in a general data transmission process.

2-3. Base Station

(1) Configuration Example of Device

FIG. 13 is a block diagram illustrating an example of a configuration ofthe base station 220 in accordance with this embodiment. Referring toFIG. 13, the base station 220 includes a wireless reception unit 122, awireless transmission unit 124, a transmission unit 126, a receptionunit 128, a storage unit 230, and a communication control unit 232.

The storage unit 230 stores a program and data for processing by thecommunication control unit 232 using a storage medium. In addition, thestorage unit 230 may pre-store at least part of the control informationillustrated in FIG. 3 in association with a terminal ID or addressinformation of each terminal device 200. In addition, in thisembodiment, the storage unit 230 pre-stores intermediate node dataobtained by listing candidates for the intermediate node to bedesignated for the data packet.

FIGS. 14A and 14B are explanatory diagrams each illustrating an exampleof intermediate node data. Referring to FIG. 14A, intermediate node data231 a is illustrated as the first example. The intermediate node data231 a has two data items such as an “AP class” and an “intermediatenode.” In this case, the intermediate node data 231 a is data definingan intermediate node to be designated for every AP class of the datapacket. On the other hand, referring to FIG. 14B, intermediate node data231 b is illustrated as the second example. The intermediate node data231 b has two data items such as a “terminal class” and an “intermediatenode.” In this case, the intermediate node data 231 b is data definingan intermediate node to be designated for every terminal class of thedata packet. The present disclosure is not limited to these examples.The intermediate node data may be data defining an intermediate node inassociation with arbitrary control information as illustrated in FIG. 3.

The communication control unit 232, for example, causes the base station220 to operate as a base station for cellular communication according tostandard specs of LTE, LTE-A, or the like. In addition, in thisembodiment, the communication control unit 232 can insert intermediatenode designation information designating an intermediate node differentfrom the ultimate destination node of the data packet into thedestination field of the data packet received by the wireless receptionunit 122. For example, when the data packet from the terminal device 200is input from the wireless reception unit 122, the communication controlunit 232 can specify an intermediate node associated with an AP class ora terminal class described within the data packet using theabove-described intermediate node data stored by the storage unit 230.The communication control unit 232 inserts the intermediate nodedesignation information designating the specified intermediate node intothe destination field of the data packet. Here, a plurality of patternsof a process of updating the destination field will be described laterin detail in an example. The communication control unit 232 maydesignate a different intermediate node for every data packet, forexample, in a round-robin scheme or a random scheme, from a plurality ofintermediate node candidates.

In addition, the communication control unit 232 may insert controlinformation to be used for enabling the intermediate node to identifythe ultimate destination node of the data packet into the data packettransmitted from the terminal device 200 instead of the terminal device200. The control information to be used for identifying the ultimatedestination node, for example, can include at least one of pieces of thecontrol information described using FIG. 3.

(2) Example of Destination Field Update Process

FIGS. 15A to 15E are explanatory diagrams each illustrating an exampleof the destination field update process by the communication controlunit 232 in accordance with this embodiment in each drawing, content ofdestination fields before and after the update by the communicationcontrol unit 232 is illustrated.

In the first example illustrated in FIG. 15A, the communication controlunit 232 simply overwrites information regarding the destination nodeinserted into the destination field F1 of the data packet over theintermediate node designation information (for example, an IP address, ahost name, or the like of the intermediate node). In this case, thedestination field update process can be most easily implemented.

In the second example illustrated in FIG. 15B, the communication controlunit 232 overwrites information regarding the destination node insertedinto the destination field F1 of the data packet over the intermediatenode designation information (F1 b), and adds a flag indicating that thedestination field F1 has been changed to the data packet (F1 a). In thiscase, the intermediate node receiving the data packet after the updatecan know whether the destination field F1 has been changed by referringto the flag. A position of the flag within the data packet may be aposition different from the position illustrated in FIG. 15B.

In the third example illustrated in FIG. 15C, the destination field F1is pre-divided into a flag sub-field F1 a and a node-informationsub-field F1 b. In this case, for example, the terminal device 200transmits a data packet in which the flag of the sub-field F1 a has beenset to zero and information regarding the destination node has beeninserted into the sub-field F1 b. The communication control unit 232 ofthe base station 220 can update the flag of the sub-field F1 a to 1, andoverwrite the sub-field F1 b over the intermediate node designationinformation. In this case, all communication nodes receiving the datapacket can know whether the destination field F1 has been changed byreferring to the flag sub-field F1 a.

In the fourth example illustrated in FIG. 15D, the communication controlunit 232 updates the flag to 1, inserts the intermediate nodedesignation information into the destination field F1, and transcribesinformation described in the destination field F1 upon receipt of thedata packet to a reserved field F9. In this case, the intermediate nodereceiving the data packet after the update can identify the ultimatedestination node by referring to information regarding the destinationnode described in the reserved field F9.

The fifth example illustrated in FIG. 15E is an example of thedestination field update process capable of being adopted when aplurality of intermediate nodes are sequentially designated on theoccasion of forwarding of one data packet. In this case, first, thecommunication control unit 232 of the base station 220 inserts theintermediate node designation information into the destination nodefield F1, and transcribes information designating the ultimatedestination node (destination node 1) to the reserved field F9. Next,the intermediate node receiving the data packet inserts new intermediatenode designation information into the destination field F1, and furthertranscribes original intermediate node designation information describedin the destination field F1 to the reserved field F9. At this time,instead of flags of two values indicating the presence and absence ofthe update, it is desirable to add information indicating the number ofupdates to the data packet (increment the number of updates). Thereby,the intermediate node receiving the data packet after the update caneasily know the number of pieces of node information transcribed to thereserved field F9. In the fifth example, because the reserved field F9represents a history of designation of the intermediate node, it ispossible to prevent a looped communication path from being formed bydesignating one intermediate node a plurality of times.

(3) Flow of Data Forwarding Process

FIGS. 16A and 16B are flowcharts each illustrating an example of theflow of the data forwarding process by the base station 220 inaccordance with this embodiment.

FIG. 16A illustrates an example of a flow including the destinationfield update process illustrated in FIGS. 15A to 15C. In the example ofFIG. 16A, first, the wireless reception unit 122 of the base station 220receives a data packet transmitted from the terminal device 200 (stepS222). The wireless reception unit 122 outputs the received data packetto the communication control unit 232. Next, the communication controlunit 232 determines whether the received data packet is a packet for MTCcommunication (step S224). Here, if the data packet is the packet forthe MTC communication, then the process of steps S226 to S232 isperformed.

When a device of a transmission source is an MTC terminal, thecommunication control unit 232 specifies an intermediate node to bedesignated in the destination field of the data packet usingintermediate node data (step S226). Next, the communication control unit232 inserts the intermediate node designation information designatingthe specified intermediate node into the destination field of the datapacket (step S230). Next, the communication control unit 232 sets a flag(for example, Flag=1) indicating that the destination field has beenchanged in the data packet (step S232).

The data packet is forwarded from the transmission unit 126 to the corenetwork 10 (step S234).

FIG. 16B illustrates an example of a flow including the destinationfield update process illustrated in FIGS. 15D and 15E. In the example ofFIG. 16B, first, the wireless reception unit 122 of the base station 220receives a data packet transmitted from the terminal device 200 (stepS222). The wireless reception unit 122 outputs the received data packetto the communication control unit 232. Next, the communication controlunit 232 determines whether the received data packet is a packet for MTCcommunication (step S224). Here, if the data packet is the packet forthe MTC communication, then the process of steps S226 to S233 isperformed.

When the device of the transmission source is the MTC terminal, thecommunication control unit 232 specifies an intermediate node to bedesignated in the destination field of the data packet using theintermediate node data (step S226). Next, the communication control unit232 transcribes information regarding the destination node described inthe destination field upon receipt of the data packet to another fieldsuch as the reserved field (step S228). Next, the communication controlunit 232 inserts the intermediate node designation informationdesignating the specified intermediate node into the destination fieldof the data packet (step S230). Next, the communication control unit 232updates the flag (step S233).

The data packet is forwarded from the transmission unit 126 to the corenetwork 10 (step S234).

2-4. Intermediate Node

(1) Configuration Example of Device

FIG. 17 is a block diagram illustrating an example of a configuration ofthe communication device 240 that operates as the intermediate node.Referring to FIG. 17, the communication device 240 includes a receptionunit 142, a transmission unit 144, a storage unit 250, a communicationcontrol unit 252, and an information management unit 254.

The storage unit 250 stores programs and data for processing by thecommunication control unit 252 and the information management unit 254using a storage medium. In addition, in this embodiment, the storageunit 250 may store destination node data in which control informationwithin the data packet is associated with the destination node of thedata packet as will be described later. In addition, like the storageunit 150 of the communication device 140 in accordance with the firstembodiment, the storage unit 250 may store forwarding destination datain which the control information within the data packet is associatedwith the forwarding destination node of the data packet.

The communication control unit 252 identifies an ultimate destinationnode of the data packet from information included in a field differentfrom the destination field when the reception unit 142 receives the datapacket in which its own device is designated in the destination field.More specifically, the communication control unit 252, for example, canidentify the ultimate destination node for every data packet usingdestination node data in which the control information within the datapacket is associated with the destination node of the data packet.

FIG. 18 is an explanatory diagram illustrating an example of destinationnode data capable of being stored by the storage unit 250. Referring toFIG. 18, as an example, destination node data 251 has four data itemssuch as an “AP class,” a “terminal class,” a “provider,” and a“destination node.” Among these, a combination of the “AP class,” the“terminal class,” and the “provider” becomes an identification key foridentifying one destination node. For example, a data packet in whichthe AP class is “C1,” the terminal class is “T3,” and the provider is“J01” corresponds to a destination node D1. The data packet in which theAP class is “C1,” the terminal class is “T3,” and the provider is “J02”corresponds to a destination node D2 (description of the remainingrecords is omitted). Control information available as the identificationkey for identifying the destination node is not limited to this example.For example, an arbitrary item among the control information illustratedin FIG. 3 (or other control information) may be used as theidentification key for identifying the destination node in thisembodiment, the above-described destination node data can be managed inthe information management server 270 illustrated in FIG. 10 and sharedbetween intermediate nodes.

The communication control unit 252 can identify the destination nodecorresponding to the control information within the data packet as theultimate destination node using the above-described destination nodedata. When a device (for example, the above-described base station 220)designating the intermediate node transcribes information regarding thedestination node to the reserved field, the communication control unit252 can identify the ultimate destination node without using thedestination node data. In this case, the storage unit 250 may not storethe destination node data illustrated in FIG. 18.

The communication control unit 252 inserts destination node designationinformation designating the destination node identified as describedabove into the destination field of the data packet. That is, thecommunication control unit 252 corrects information of the temporarilydesignated destination field to information of the destination node atwhich the data packet should ultimately arrive. The communicationcontrol unit 252 causes the transmission unit 144 to transmit a datapacket in which the ultimate destination node designation information isincluded in the destination field.

The communication control unit 252 may select a forwarding destinationnode (the next hop) of the data packet from a plurality of forwardingdestination node candidates so that traffic is distributed as in theforwarding node in accordance with the first embodiment. In addition, byinserting intermediate node designation information designating aseparate intermediate node instead of the ultimate destination node intothe destination field, the communication control unit 252 may furtherforward the data packet to the separate intermediate node.

The information management unit 254 acquires update data for updatingthe destination node data stored by the storage unit 250 from theinformation management server 270, and updates the destination node datausing the acquired update data. The information management unit 254 mayrequest the information management server 270 to periodically distributethe update data at a constant frequency. Alternatively, when the updatedata has been received from the information management server 270, theinformation management unit 254 may passively update the destinationnode data.

(2) Flow of Data Forwarding Process

FIGS. 19A and 19B are flowcharts each illustrating an example of a flowof a data forwarding process by the communication device 240 inaccordance with this embodiment.

FIG. 19A illustrates an example of a flow including a destination nodeidentification process using destination node data. In the example ofFIG. 19A, first, the reception unit 142 of the communication device 240receives a data packet transmitted from the terminal device 200 (stepS242). The reception unit 142 outputs the received data packet to thecommunication control unit 252. Next, the communication control unit 252determines whether the received data packet is a packet for MTCcommunication (step S244). Here, if the data packet is the packet forthe MTC communication, the process proceeds to step S246. On the otherhand, if the data packet is not the packet for the MTC communication,the process proceeds to step S254.

In step S246, the communication control unit 252 acquires controlinformation included in the header area of the data packet (step S246).Next, the communication control unit 252, for example, identifies aforwarding destination node corresponding to a combination of an APclass, a terminal class, and a provider included in the acquired controlinformation using destination node data (step S248). The communicationcontrol unit 252 inserts destination node designation informationdesignating the identified destination node into the destination fieldof the data packet (step S250). At this time, the communication controlunit 252 updates a value of the flag within the data packet ifnecessary.

The transmission unit 144 forwards the data packet to the next hop (forexample, a forwarding destination node or a predetermined communicationnode selected so that traffic is distributed) (step S254).

FIG. 19B illustrates an example of a flow of a data forwarding processnot using destination node data. In the example of FIG. 19B, first, thereception unit 142 of the communication device 240 receives a datapacket transmitted from the terminal device 200 (step S242). Thereception unit 142 outputs the received data packet to the communicationcontrol unit 252. Next, the communication control unit 252 determineswhether the received data packet is a packet for MTC communication (stepS244). Here, if the data packet is the packet for the MTC communication,the process proceeds to step S247. On the other hand, if the data packetis not the packet for MTC communication, the process proceeds to stepS254.

In step S247, the communication control unit 252 determines whether thedestination field has been changed by referring to a flag within thedata packet (step S247). Here, when the destination field has beenchanged, the process proceeds to step S249. On the other hand, when thedestination field has not been changed, the process proceeds to stepS254.

In step S249, the communication control unit 252 identifies adestination node from information transcribed to the reserved fieldwithin the data packet (step S249). The communication control unit 252inserts destination node designation information designating theidentified destination node into the destination field of the datapacket (step S252). At this time, the communication control unit 252updates a value of the flag within the data packet if necessary.

The transmission unit 144 forwards the data packet to the next hop (forexample, a forwarding destination node or a predetermined communicationnode selected so that traffic is distributed) (step S254).

2-5. Example of Communication Path

FIG. 20 is an explanatory diagram illustrating the example of thecommunication path capable of being implemented in accordance with thisembodiment. Referring to FIG. 20, as an example, three communicationpaths R1, R2, and R3 simplified between the terminal device 200, whichis a transmission source of MTC communication, and the AP server 190,which is a destination, are illustrated. Control signaling, which iscollaterally performed, such as an acknowledgement (ACK) and a negativeacknowledgement (MACK) is not illustrated in the drawing. Thecommunication path R1 is a shortest path (having an optimum routingmetric) between the terminal device 200 and the AP server 190. On theother hand, the communication paths R2 and R3 are redundant paths thatbypass some links included in the communication path R1.

For example, when the terminal device 200 or the base station 220 hasdesignated an intermediate node M1 in the destination field of the datapacket, the data packet can reach the AP server 190 via thecommunication path R2. In addition, for example, when the terminaldevice 200 or the base station 220 has designated an intermediate nodeM2 and the intermediate node M2 has further designated an intermediatenode M3, the data packet can reach the AP server 190 via thecommunication path R3. By causing the data packet of the MTCcommunication to bypass the shortest path as described above, thetraffic is distributed and the concentration of traffic on a specificcommunication path is prevented in advance.

2-6. Information Management Server

(1) Configuration Example of Device

FIG. 21 is a block diagram illustrating an example of a configuration ofthe information management server 270 in accordance with thisembodiment. Referring to FIG. 21, the information management server 270includes a reception unit 272, a transmission unit 274, a storage unit280, and an information management unit 282.

The reception unit 272 and the transmission unit 274 are communicationinterfaces for enabling the information management server 270 tocommunicate with other communication devices.

The storage unit 280 stores a master of the destination node data havingsubstantially the same data items as the destination node dataillustrated in FIG. 18 using a storage medium. In addition, the storageunit 280 may store a master of intermediate node data havingsubstantially the same data items as the intermediate node dataillustrated in FIGS. 14A and 14B. Further, the storage unit 280 maystore a master of forwarding destination data described in the firstembodiment.

The information management unit 282 provides a master managementfunction for information stored by the storage unit 280. For example,the information management unit 282 provides an interface for acceptingregistration of new information regarding an AP when the AP server 190has been newly introduced into the communication system 2. Theinterface, for example, may be a graphic user interface (GUI) thataccepts an information input from a user on a screen of a device.Alternatively, the interface, for example, may be an application programinterface (API) that receives registration information from the APserver 190, in addition, the interface provided by the informationmanagement unit 282 may accept a change and deletion of registeredinformation. When an update of a master (addition, change, or deletionof information) occurs, the information management unit 282 distributesupdate data based on a difference in the master to communication nodesincluded in the communication system 2.

(2) Example of Update Data

FIG. 22 is an explanatory diagram illustrating the example of the updatedata. For example, it is assumed that a provider J01 has introduced newAP servers D1, D3, and D5. In this case a user (engineer) of theprovider J01 registers information regarding each of the AP servers D1,D3, and D5 in the information management server 270 via a user interfaceprovided by the information management unit 282. Here, the registeredinformation, for example, can include an AP class, a terminal class, acommunication schedule for MTC communication, and the like correspondingto each AP server. As a result, the information management unit 282updates a master of destination node data stored by the storage unit280, and generates update data 283 as illustrated in FIG. 22.

Referring to FIG. 22, the update data 283 is data describing informationregarding a corresponding AP class, terminal class, and communicationschedule for every application server, which can serve as a candidatefor the destination node, using a provider ID as a key. An “updatedivision” having a value of “addition,” “change,” “deletion,” or thelike is assigned to each record of the update data 283. An intermediatenode receiving the above-described update data 283 from the informationmanagement server 270 causes separately stored destination node data tobe synchronized with a latest master using the update data 283.

(3) Flow of Update Data Distribution Process

FIGS. 23A and 23B are flowcharts each illustrating an example of theflow of the update data distribution process by the informationmanagement server 270 in accordance with this embodiment.

FIG. 23A illustrates an example in which update data is distributed toan intermediate node every time a master is updated. In the example ofFIG. 23A, first, the information management unit 282 of the informationmanagement server 270 acquires registration information for the APserver 190 via a GUI (or from the AP server 190) (step S272). Next, theinformation management unit 282 updates a master of destination nodedata stored by the storage unit 280 using the acquired registrationinformation (step S274). Next, the information management unit 282generates update data as illustrated in FIG. 22 based on a difference inthe master generated by the update (step S276). The transmission unit274 distributes the update data generated by the information managementunit 282 to each intermediate node (step S278). The update data may bebroadcast to each intermediate node, and may be separately unicast ormulticast.

FIG. 23B illustrates an example in which update data is distributed toan intermediate node according to a request from the intermediate node.In the example of FIG. 23B, when an update data distribution request isreceived by the reception unit 272 of the information management server270 from the intermediate node, the process proceeds to step S284 (stepS282). In step S284, the information management unit 282 determineswhether a difference has occurred in a master of destination node dataafter previous distribution of update data (step S284). Here, when thedifference has occurred in the master of the destination node data, theinformation management unit 282 generates update data based on thedifference in the master (step S286). The transmission unit 274distributes the update data generated by the information management unit282 to an intermediate node of a request source (step S278). On theother hand, when the difference has not occurred in the master of thedestination node data, the information management unit 282 notifies theintermediate node of the request source that there is no difference(step S289).

The present disclosure is not limited to the examples of FIGS. 23A and23B, and the information management server 270, for example, maydetermine the presence/absence of the difference in the masterperiodically at a constant frequency, and actively distribute updatedata to each intermediate node when the difference has occurred.

(4) Flow of Data Update Process

FIG. 24 is a flowchart illustrating an example of the flow of thedestination node data update process by the intermediate node inaccordance with this embodiment.

Referring to FIG. 24, first, the reception unit 142 of the communicationdevice 240 receives update data of destination node data distributedfrom the information management server 270 (step S291). Next, theinformation management unit 254 determines whether there is a new APclass within the update data (step S292). Here, when there is a new APclass within the update data, the new AP class is added to thedestination node data 251 illustrated in FIG. 18 (step S293). Inaddition, the information management unit 254 determines whether thereis a new terminal class within the update data (step S294). Here, whenthere is a new terminal class within the update data, the new terminalclass is added to the destination node data 251 (step S295). Further,the information management unit 254 determines whether the provider IDwithin the update data is a provider ID of a new provider (step S296).Here, when the provider ID within the update data is a provider ID of anew provider, the provider ID of the new provider is added to thedestination node data 251 (step S297). The information management unit254 adds (information such as an IP address or a host name of adestination node corresponding to a combination of an AP class, aterminal class, and a provider ID within update data to the destinationnode data 251, or updates an existing destination node (step S298).

2-7. Management of DRX

Communication schedule information included in update data 283illustrated in FIG. 22 can be further distributed from the intermediatenode to each corresponding terminal device 200. Alternatively theinformation management server 270 may distribute the communicationschedule information separate from the update data 283 to each terminaldevice 200. Each terminal device 200 receiving the communicationschedule information controls a sleep time of its own device accordingto the communication schedule information, and implements anintermittent operation (DRX: discontinuous reception).

The control of the intermittent operation of the terminal device 200 maybe performed according to a simple parameter such as once daily (“everyday”) or once weekly (“every week”) like the communication scheduleinformation illustrated in FIG. 22. For example, when the parameter ofonce daily (“every day”) has been designated, the wireless receptionunit 122 and the wireless transmission unit 124 of the terminal device200 wake up in an arbitrary time band only once daily, and transmit theabove-described data packet to the AP server 190 by generating AP datain the time band. The communication schedule information may includeinformation regarding a time band of the wake-up (for example, start andend times, a time length, or the like) in addition to a cycle of theintermittent operation.

In addition, in each terminal device 200, according to the base station220 or another communication node, a cycle of a shorter auxiliaryintermittent operation in the time band of the above-described wake-upmay be determined. In this case, the wireless reception unit 122 and thewireless transmission unit 124 of the terminal device 200 can steep, forexample, except for the timing at which a communication resource for itsown device has been scheduled, even in the designated wake-up time band.Thereby, power consumption of the terminal device 200 can be furtherreduced.

2-8. Summary of Second Embodiment

The second embodiment has been described above using FIGS. 10 to 24. Inaccordance with this embodiment, intermediate node designationinformation designating an intermediate node different from adestination node of a data packet on a path to the destination node isinserted into the destination field of a data packet transmitted from anMTC terminal. Thereby, traffic of MTC communication is not concentratedon a specific communication path, and bypasses to a path via thedesignated intermediate node. As a result, traffic is distributed andcongestion of traffic in MTC communication is avoided or mitigated.

In addition, in accordance with this embodiment, a device that insertsthe intermediate node designation information into the destination fieldmay be a communication node (for example, a base station or the like)that receives a data packet from the MTC terminal. When theabove-described communication node inserts the intermediate nodedesignation information into the data packet, it is possible tointroduce a technique of congestion avoidance in accordance with theabove-described embodiment without giving impact such as modification ofa processing logic to the MTC terminal.

In addition, in accordance with this embodiment, the designatedintermediate node identifies an ultimate destination node of a datapacket from control information regarding the MTC terminal insertedwithin the data packet or information transcribed to the reserved field.Accordingly, even when the destination field of the data packet has beenchanged, the data packet can be appropriately delivered to the ultimatedestination node (for example, a corresponding AP server) via theintermediate node.

In this embodiment, because it is not necessary to transcribeinformation regarding a destination node to the reserved field when thedestination node is identified using the control information regardingthe MTC terminal, an existing packet format can be effectively utilized.On the other hand, because each intermediate node does not holddestination node data when the destination node is identified frominformation transcribed to the reserved field, it is possible to reduceprocessing costs necessary for referring to the destination node data orresources of a storage medium.

2-9. Application Example

In the second embodiment, an example in which a data packet transmittedfrom an MTC terminal is bypassed to a path via an intermediate node hasbeen mainly described. However, a mechanism for setting theabove-described intermediate node is also applicable to a data packettransmitted to the MTC terminal. For example, the communication device140 illustrated in FIG. 10 may insert intermediate node designationinformation into the destination field of the data packet transmitted tothe terminal device 200 according to a destination field update processillustrated in FIG. 15D or 15E, and transcribe information such as anaddress of the terminal device 200 described in the destination field tothe reserved field.

A series of control processes by each device described in thisspecification may be implemented using one of software, hardware, and acombination of software and hardware. A program constituting thesoftware, for example, is pre-stored in a storage medium provided insideor outside each device. Each program, for example, is read to a randomaccess memory (RAM) during execution, and executed by a processor suchas a central processing unit (CPU).

In addition, an example in which the terminal devices 100 and 200, whichare MTC terminals, access a network according to wireless communicationhas been mainly described in this specification. However, the effects ofthe above-described two embodiments can be equally obtained even whenthe MTC terminals access the network according to wired communication.

The preferred embodiments of the present invention have been describedabove with reference to the accompanying drawings, whilst the presentinvention is not limited to the above examples, of course. A personskilled in the art may find various alternations and modificationswithin the scope of the appended claims, and it should be understoodthat they will naturally come under the technical scope of the presentinvention.

REFERENCE SIGNS LIST

-   -   1, 2 Communication system    -   10 Core network    -   20 Network    -   100, 200 Terminal device    -   120, 220 Base station    -   140 Communication device (forwarding node)    -   240 Communication device (intermediate node)    -   270 Information management server    -   190 AP server

The invention claimed is:
 1. A communication device, comprising:circuitry configured to: insert, into a destination field of a datapacket, intermediate node designation information designating anintermediate node different from a destination node of the data packet;insert, into the data packet, control information that enables theintermediate node to identify the destination node of the data packet orfinal destination node designation information; and transmit the datapacket into which the intermediate node designation information isinserted.
 2. The communication device according to claim 1, wherein thecircuitry is further configured to: receive the data packet transmittedfrom a terminal device or transmitted to the terminal device; and insertthe intermediate node designation information into the destination fieldof the data packet when the terminal device is a machine-typecommunication (MTC) terminal.
 3. The communication device according toclaim 2, wherein the circuitry is further configured to specify anintermediate node to be designated for the data packet from a pluralityof intermediate node candidates.
 4. The communication device accordingto claim 2, wherein the circuitry is further configured to insert theintermediate node designation information by transcribing informationdescribed in the destination field upon receipt of the data packet tothe another field.
 5. The communication device according to claim 4,wherein the circuitry is further configured to add a flag indicatingthat the destination field is changed to the data packet.
 6. Thecommunication device according to claim 1, wherein the circuitry isfurther configured to insert the control information that enables theintermediate node to identify the destination node of the data packetinto the data packet.
 7. The communication device according to claim 1,wherein the communication device is one of a plurality of intermediatenode candidates.
 8. The communication device according to claim 1,wherein the communication device is a terminal configured to generatethe data packet.
 9. A communication control method, comprising:inserting, by circuitry of a communication device into a destinationfield of a data packet, intermediate node designation informationdesignating an intermediate node different from a destination node ofthe data packet; inserting, by the circuitry into the data packet,control information that enables the intermediate node to identify thedestination node of the data packet or final destination nodedesignation information; and transmitting, by the circuitry, the datapacket into which the intermediate node designation information isinserted.
 10. A communication device, comprising: circuitry configuredto: receive a data packet transmitted from a terminal device ortransmitted to the terminal device, wherein the communication device isdesignated in a destination field; identify a destination node of thedata packet from information included in a field within the data packet,and insert destination node designation information designating theidentified destination node into the destination field; and transmit thedata packet into which the destination node designation information isinserted.
 11. The communication device according to claim 10, furthercomprising: memory configured to store destination node data in whichcontrol information within the data packet is associated with thedestination node of the data packet, wherein the circuitry is configuredto identify the destination node of the data packet using thedestination node data.
 12. The communication device according to claim11, wherein the control information includes information specifying aterminal identifier (ID), a class, or a group of the terminal device, anapplication (AP) ID or a class of an AP relating to the data packet, ora provider that provides the AP.
 13. The communication device accordingto claim 11, wherein the circuitry is further configured to: acquireupdate data for updating the destination node data from an informationmanagement server; and update the destination node data using theacquired update data.
 14. The communication device according to claim10, wherein the circuitry is further configured to identify thedestination node of the data packet from information transcribed fromthe destination field to a field different from the destination field.15. A communication control method for use in a communication devicewithin a communication network including a plurality of communicationnodes, comprising: receiving, by circuitry of the communication device,a data packet transmitted from a terminal device or transmitted to theterminal device, wherein the communication device is designated in adestination field; identifying, by the circuitry, a destination node ofthe data packet from information included in a field within the datapacket; inserting, by the circuitry, destination node designationinformation designating the identified destination node into thedestination field; and transmitting, by the circuitry, the data packetinto which the destination node designation information is inserted. 16.A communication system, comprising: a first communication deviceincluding first circuitry configured to: insert, into a destinationfield of a data packet, intermediate node designation informationdesignating an intermediate node different from a destination node ofthe data packet; and transmit the data packet into which theintermediate node designation information is inserted; and a secondcommunication device including second circuitry configured to: receive adata packet transmitted from a terminal device or transmitted to theterminal device, wherein the communication device is designated in adestination field; identify a destination node of the data packet frominformation included in a field within the data packet, and insertdestination node designation information designating the identifieddestination node into the destination field; and transmit the datapacket into which the destination node designation information isinserted, wherein the second communication device is a candidate for theintermediate node.
 17. A communication device, comprising: memoryconfigured to store destination node data that associates controlinformation within a data packet, transmitted from a terminal ortransmitted to the terminal, with a destination node to which the datapacket is to be transmitted, the control information being separate fromdestination node designation information included in the data packet;and circuitry configured to: manage an update of the destination nodedata stored by the memory; and transmit update data relating to thedestination node data to an intermediate node different from thedestination node.
 18. The communication device according to claim 17,wherein the control information includes information specifying aterminal ID, a class, or a group of a terminal, an AP ID or a class ofan AP relating to the data packet, or a provider that provides the AP.19. The communication device according to claim 17, wherein theintermediate node is configured to determine the destination node towhich the data packet is to be transmitted based on the destination nodedata and the control information.